Salesforce

Salesforce.com's Chatter, SocialText Signals, and Yammer are all examples of:

A) corporate microblogging services.
B) industry-specific social networks.
C) blogs by company executives used for aggregating customer opinion.
D) private, in-house wikis for setting meeting agendas to building multimedia training for new hires.
E) keyword-based classification systems created by user communities.